104206-82-8

Usage

Chemical and Physical Properties

Mesotrione is a light yellow opaque solid with a faint pleasant odour. It dissolves at a rate of 2.2 g/l at 200 C in unbuffered water whose pH is 4.8. It also dissolves in n-heptane <0.5, xylene 1.6, toluene 3.1, methanol 4.6, ethyl acetate 18.6, 1,2-dichloroethane 66.3, acetone 93.3, and in acetonitrile 117.0, all in g/l at 200 C. Mesotrione has a molecular weight of 339.318 g/mol, a monoisotopic mass of 339.041 g/mol and an exact mass of 339.041 g/mol. It has a heavy atom count of 23 and a complexity of 627.

Mechanism of Action

Studies indicate that the toxic influence of the compound can be attributed to high plasma concentration levels of tyrosine which is resultant of inhibition by 4-hydroxyphenylpyruvate dioxygenase (HPPD). HPPD is an essential constituent of the biochemical route that aids the conversion of tyrosine to alpha-tocopherol and plastoquino\ne. Mesotrione is a highly potent agonist of HPPD against Arabidopsis thaliana, which is indicated by the Ki figure of c 6-18 pM. It is readily absorbed by weed species after foliar application and it is widely distributed to various parts of the plant through basipetal and acropetal movement. Maize crops are generally tolerant to Mesotrione as a result of selective metabolism by the plant. The compound may take a relatively long time to be absorbed in some weed species hence Mesotrione is applied as a selective herbicide in maize plantations. The plasma half-life of the compound is approximately 1 hour.

Preparation

Mesotrione is synthesized through the reaction of acetyl chloride with 3-methylmercaptonitrobenzene with aluminum trichloride as the catalyst. The relative ketone is oxidized with sodium oxychloride which results in the 4-methylsulfonyl compound, which is condensed with cyclohexane-1,3-dione to obtain the respective enol ester. The latter is reorganized to the appropriate form of the product with potassium cyanide with triethylamine as the catalyst.? Mesotrione is available as a soluble solid or concentrates, as a pressurized liquid, a ready to use solution, soluble concentrate, emulsifiable concentrate, water dispersible granules and in granular form.? Some of its premix partners may include terbuthylazine, Rimsulfron, Nicosulfron, S-Metolachlor, Glyphosphate and Atrazine.

Consumption

A study indicated that the total usage of the compound in the last 5 years is primarily in corn, which accounts for about 98% of the total acres treated and the total pounds of the applied Mesotrione. Field corn accounts for the highest percentage of the treated crops in regards to the acres treated and the acreage of crops grown at 20.2%.

Precautionary Statements

The applicator should put on protective gear when handling Mesotrione concentrate or contaminated surfaces. It is recommended that one avoids eating, drinking or smoking while handling the product and that one should always wash off any splashes that come into contact with the skin immediately.? During the application process, the sprayer should ensure that the machine is calibrated appropriately, the nozzles are in a matched set and the machine is adjusted to the respective level of the crop. The concentrates should not be left in the sprayer for extended periods of time.? Mesotrione may cause mild or acute eye irritation. However, it is not a dermal irritant.

Uses

Different sources of media describe the Uses of 104206-82-8 differently. You can refer to the following data:
1. Mesotrione is a herbicide that works by inhibiting 4-hydroxyphenylpyruvate dioxygenase (HPPD), a crucial enzyme for the biosynthesis of carotenoid in plants. Mesotrione is also a synthetic analog of l epospermone.
2. Herbicide.

Definition

ChEBI: An aromatic ketone that is cyclohexa-1,3-dione in which one of the hydrogens at position 2 is substituted by a 4-(methanesulfonyl)-2-nitrobenzoyl group.

InChI:InChI=1/C14H13NO7S/c1-23(21,22)8-5-6-9(10(7-8)15(19)20)14(18)13-11(16)3-2-4-12(13)17/h5-7,13H,2-4H2,1H3

Synthetic route

3-(4'-methylsulfonyl-2'-nitro-benzoyloxy)-2-cyclohexene-1-one (226944-49-6) → mesotrione (104206-82-8)

Conditions	Yield
With caesium carbonate; 1,8-diazabicyclo[5.4.0]undec-7-ene at 20 - 30℃; for 2h; Reagent/catalyst; Temperature;	95%
With 6-chloro-7H-purine at 60 - 65℃; for 4h;	92.3%
With triethylamine; 2-hydroxy-2-methylpropanenitrile In acetonitrile at 20℃; for 10h; Inert atmosphere;	54%

4-methylsulphonyl-2-nitrobenzoyl chloride (110964-80-2) + 1,3-cylohexanedione (504-02-9) → mesotrione (104206-82-8)

Conditions	Yield
With triethylamine; 2-hydroxy-2-methylpropanenitrile In dichloromethane at 15℃; Large scale;	89.66%
With triethylamine In dichloromethane at 35 - 40℃;	88.74%
Stage #1: 4-methylsulphonyl-2-nitrobenzoyl chloride; 1,3-cylohexanedione In dichloromethane at 15℃; for 2h; Stage #2: With 2-hydroxy-2-methylpropanenitrile In dichloromethane at 32℃; for 3h; Temperature;	88%
Stage #1: 4-methylsulphonyl-2-nitrobenzoyl chloride; 1,3-cylohexanedione With 15-crown-5; sodium hydroxide In chloroform at 35℃; for 1.5h; Stage #2: With 15-crown-5; sodium hydroxide; N,N,N',N'-tetramethylguanidine In chloroform at 350℃; for 3.5h; Solvent; Temperature;	88.98%

4-methanesulfonyl-2-nitro-benzoic acid (110964-79-9) + 1,3-cylohexanedione (504-02-9) → mesotrione (104206-82-8)

Conditions	Yield
Stage #1: 4-methanesulfonyl-2-nitro-benzoic acid; 1,3-cylohexanedione With dicyclohexyl-carbodiimide In 5,5-dimethyl-1,3-cyclohexadiene at 140 - 150℃; Stage #2: In 5,5-dimethyl-1,3-cyclohexadiene; acetonitrile Solvent;	80.3%

C14H13NO5S → mesotrione (104206-82-8)

Conditions	Yield
With diethylene glycol dibutyl ether; oxygen at 150℃; for 20h; Green chemistry;	72%
With diethylene glycol dibutyl ether; oxygen at 150℃; for 20h;	72%

1-(2-Nitro-4-methanesulphonylbenzoyl)-1,2,4-triazole + 1,3-cylohexanedione (504-02-9) → mesotrione (104206-82-8)

Conditions	Yield
With potassium carbonate In water; acetonitrile

1,2,4-Triazole (288-88-0) + 3-(4'-methylsulfonyl-2'-nitro-benzoyloxy)-2-cyclohexene-1-one (226944-49-6) → mesotrione (104206-82-8)

Conditions	Yield
In potassium carbonate

1-fluoro-4-methanesulfonyl-2-nitrobenzene (453-72-5) → mesotrione (104206-82-8)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: sodium hydroxide / dimethyl sulfoxide / 3 h / 310 °C 1.2: 3 h 2.1: thionyl chloride / Reflux 3.1: triethylamine / toluene / 20 - 30 °C 4.1: benzyl triethylammonium azide; triethylamine / 50 °C View Scheme

1-chloro-4-methanesulfonyl-2-nitrobenzene (97-07-4) → mesotrione (104206-82-8)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: sodium hydroxide / dimethyl sulfoxide / 1 h / 60 °C 1.2: 2 h 2.1: thionyl chloride / Reflux 3.1: triethylamine / toluene / 20 - 30 °C 4.1: benzyl triethylammonium azide; triethylamine / 50 °C View Scheme

4-methanesulfonyl-2-nitro-benzoic acid (110964-79-9) → mesotrione (104206-82-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: thionyl chloride / Reflux 2: triethylamine / toluene / 20 - 30 °C 3: benzyl triethylammonium azide; triethylamine / 50 °C View Scheme
Multi-step reaction with 3 steps 1: phosgene / toluene; N,N-dimethyl-formamide / 2 h / 70 - 80 °C 2: potassium carbonate / 8 h / 55 °C 3: 6-chloro-7H-purine / 4 h / 60 - 65 °C View Scheme
Multi-step reaction with 3 steps 1: thionyl chloride; N,N-dimethyl-formamide / 1,2-dichloro-ethane / 6.5 h / 65 - 69 °C / Inert atmosphere 2: triethylamine / dichloromethane / 20 °C 3: triethylamine; 2-hydroxy-2-methylpropanenitrile / acetonitrile / 10 h / 20 °C / Inert atmosphere View Scheme

1-methyl-4-(methylsulfonyl)-2-nitrobenzene (1671-49-4) → mesotrione (104206-82-8)

Conditions	Yield
Multi-step reaction with 4 steps 1: vanadia; nitric acid / 135 - 160 °C 2: thionyl chloride; N,N-dimethyl-formamide / 1,2-dichloro-ethane / 6 h / 60 - 65 °C 3: triethylamine / 1,2-dichloro-ethane / 1 h / 5 - 35 °C 4: triethylamine; 2-hydroxy-2-methylpropanenitrile / 5 h / 20 - 25 °C View Scheme
Multi-step reaction with 4 steps 1.1: vanadia; sulfuric acid; nitric acid / 13 h / 145 - 165 °C 2.1: N,N-dimethyl-formamide / dichloromethane / 0.5 h 2.2: 5 h / 30 - 80 °C 3.1: tetrabutylammomium bromide / water; dichloromethane / 6 h / 2 °C 4.1: triethylamine / dichloromethane / 0.25 h / 30 °C 4.2: 3 h / 30 °C View Scheme
Multi-step reaction with 3 steps 1.1: oxygen; cobalt(II) chloride; iron(III) sulfate / acetic acid / 300 °C / 18751.9 Torr 2.1: bis(trichloromethyl) carbonate / N,N-dimethyl-formamide / 3 h / 70 °C 3.1: 15-crown-5; sodium hydroxide / chloroform / 1.5 h / 35 °C 3.2: 3.5 h / 350 °C View Scheme

1-methyl-2-nitrobenzene (88-72-2) → mesotrione (104206-82-8)

Conditions

Yield

Multi-step reaction with 6 steps 1.1: chlorosulfonic acid / 3.5 h / 110 - 115 °C 1.2: 3 h / 60 - 65 °C 2.1: sodium sulfite; sodium carbonate / water / 3 h / 0 - 25 °C / pH 7.5 - 8 2.2: 14 h / 40 - 100 °C 3.1: vanadia; nitric acid / 135 - 160 °C 4.1: thionyl chloride; N,N-dimethyl-formamide / 1,2-dichloro-ethane / 6 h / 60 - 65 °C 5.1: triethylamine / 1,2-dichloro-ethane / 1 h / 5 - 35 °C 6.1: triethylamine; 2-hydroxy-2-methylpropanenitrile / 5 h / 20 - 25 °C View Scheme

4-methyl-3-nitrobenzenesulfonyl chloride (616-83-1) → mesotrione (104206-82-8)

Conditions

Yield

Multi-step reaction with 5 steps 1.1: sodium sulfite; sodium carbonate / water / 3 h / 0 - 25 °C / pH 7.5 - 8 1.2: 14 h / 40 - 100 °C 2.1: vanadia; nitric acid / 135 - 160 °C 3.1: thionyl chloride; N,N-dimethyl-formamide / 1,2-dichloro-ethane / 6 h / 60 - 65 °C 4.1: triethylamine / 1,2-dichloro-ethane / 1 h / 5 - 35 °C 5.1: triethylamine; 2-hydroxy-2-methylpropanenitrile / 5 h / 20 - 25 °C View Scheme

Methyl p-tolyl sulfone (3185-99-7) → mesotrione (104206-82-8)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: nitric acid; sulfuric acid / 1.17 h / Large scale 1.2: 33.5 h / 142 - 146 °C / Large scale 2.1: thionyl chloride / N,N-dimethyl-formamide / Reflux; Large scale 3.1: 2-hydroxy-2-methylpropanenitrile; triethylamine / dichloromethane / 15 °C / Large scale View Scheme
Multi-step reaction with 3 steps 1.1: sulfuric acid; nitric acid / 5.58 h 1.2: 142 - 145 °C 2.1: thionyl chloride / N,N-dimethyl-formamide / 65 °C 3.1: triethylamine / dichloromethane / 35 - 40 °C View Scheme
Multi-step reaction with 5 steps 1.1: sulfuric acid / 0.5 h / 20 °C 1.2: 10 h / 10 °C 2.1: vanadia; sulfuric acid; nitric acid / 13 h / 145 - 165 °C 3.1: N,N-dimethyl-formamide / dichloromethane / 0.5 h 3.2: 5 h / 30 - 80 °C 4.1: tetrabutylammomium bromide / water; dichloromethane / 6 h / 2 °C 5.1: triethylamine / dichloromethane / 0.25 h / 30 °C 5.2: 3 h / 30 °C View Scheme

p-toluenesulfonyl chloride (98-59-9) → mesotrione (104206-82-8)

Conditions

Yield

Multi-step reaction with 6 steps 1.1: sodium hydrogencarbonate; sodium sulfite / water / 9 h / 75 °C 1.2: 4.5 h / 45 - 130 °C 2.1: sulfuric acid / 0.5 h / 20 °C 2.2: 10 h / 10 °C 3.1: vanadia; sulfuric acid; nitric acid / 13 h / 145 - 165 °C 4.1: N,N-dimethyl-formamide / dichloromethane / 0.5 h 4.2: 5 h / 30 - 80 °C 5.1: tetrabutylammomium bromide / water; dichloromethane / 6 h / 2 °C 6.1: triethylamine / dichloromethane / 0.25 h / 30 °C 6.2: 3 h / 30 °C View Scheme

copper(II) hydroxide + mesotrione (104206-82-8) → copper chelate of 2-(2'-nitro-4'-methylsulphonylbenzoyl)-1,3-cyclohexanedione

Conditions	Yield
Stage #1: copper(II) hydroxide; mesotrione With acetic acid In water at 25 - 35℃; for 1.5 - 2h; pH=2.3 - 4.0; Stage #2: With ammonium nitrate In water

mesotrione (104206-82-8) → 2-amino-4-(methylsulfonyl)benzoic acid (393085-45-5) + 4-methanesulfonyl-2-nitro-benzoic acid (110964-79-9)

Conditions	Yield
With TiO2 Degussa P25; oxygen In water pH=4; Kinetics; Mechanism; Reagent/catalyst; pH-value; Wavelength; UV-irradiation;

mesotrione (104206-82-8) → carbon dioxide (124-38-9)

Conditions	Yield
With hematite; oxalic acid In water at 20℃; pH=4; Kinetics; Reagent/catalyst; Concentration; pH-value; UV-irradiation; Green chemistry;

mesotrione (104206-82-8) → 2-amino-4-(methylsulfonyl)benzoic acid (393085-45-5) + xanthene-1,9-dione-3,4-dihydro-6-methylsulfonyl + 2-hydroxy-4-(methylsulfonyl)-2-nitrobenzoic acid (108153-42-0) + 4-methanesulfonyl-2-nitro-benzoic acid (110964-79-9)

Conditions	Yield
With water; copper(l) chloride for 24h; pH=6.5; Kinetics; Irradiation;

mesotrione (104206-82-8) → 2-amino-4-(methylsulfonyl)benzoic acid (393085-45-5)

Conditions	Yield
In water pH=6.5;
With nitroreductase NfrA2/YncD from Bacillus megaterium Mes11 strain, His-tagged; NADH In aq. buffer at 28℃; for 1h; pH=6.5; Enzymatic reaction;

copper(l) chloride + mesotrione (104206-82-8) → C14H15CuNO7S

Conditions	Yield
In water pH=6.5;

copper(II) sulfate (7758-99-8) + mesotrione (104206-82-8) → mesotrione copper chelate

Conditions	Yield
Stage #1: mesotrione With sodium hydroxide In water for 1h; pH=7- 10; Stage #2: copper(II) sulfate In water pH=4.8-5.2; Reagent/catalyst;	555 mg

mesotrione (104206-82-8) → C14H13NO4S

Conditions	Yield
Multi-step reaction with 2 steps 1: hydrogenchloride; iron / tert-butyl methyl ether; water / 3 h / 25 - 60 °C / pH 2.5 2: water; sodium hydroxide / 0.5 h / 70 °C / pH 13.8 View Scheme

mesotrione (104206-82-8) → C14H15NO5S

Conditions	Yield
With hydrogenchloride; iron In tert-butyl methyl ether; water at 25 - 60℃; for 3h; pH=2.5; Solvent; Temperature; Reagent/catalyst; pH-value;

Upstream product

• 288-88-0 1,2,4-Triazole 
• 226944-49-6 3-(4'-methylsulfonyl-2'-nitro-benzoyloxy)-2-cyclohexene-1-one 
• 453-72-5 1-fluoro-4-methanesulfonyl-2-nitrobenzene 
• 97-07-4 1-chloro-4-methanesulfonyl-2-nitrobenzene 
• 110964-79-9 4-methanesulfonyl-2-nitro-benzoic acid 
• 3185-99-7 Methyl p-tolyl sulfone 
• 110964-80-2 4-methylsulphonyl-2-nitrobenzoyl chloride 
• 504-02-9 1,3-cylohexanedione 
• 98-59-9 p-toluenesulfonyl chloride 
• 616-83-1 4-methyl-3-nitrobenzenesulfonyl chloride 
• 88-72-2 1-methyl-2-nitrobenzene 
• 1671-49-4 1‐methyl‐4‐(methylsulfonyl)‐2‐nitrobenzene 

Downstream Products

• 393085-45-5 2-amino-4-(methylsulfonyl)benzoic acid 
• 108153-42-0 2-hydroxy-4-(methylsulfonyl)-2-nitrobenzoic acid 
• 110964-79-9 4-methanesulfonyl-2-nitro-benzoic acid 

Related news

Effects of the herbicide Mesotrione (cas 104206-82-8) on soil enzyme activity and microbial communities08/03/2019

Mesotrione (2-[4-(methylsulfonyl)-2-nithobenzoyl]-1, 3-cyclohexanedione) is a selective triketone herbicide that has been widely used in corn production for the past 15 years. However, its potential for risk to soil ecosystems is poorly documented. The present study investigated the soil enzyme ...detailed

Relevant academic research and scientific papers

Method for preparing triketone compound through continuous flow

The invention relates to a method for preparing a triketone compound through continuous flow, which uses substrate acyl chloride and 1, 3 - cyclohexanedione as a raw material and is subjected to esterification. The method is mild in condition, simple to operate, good in stability and high in reliability. Utilize continuous flow can accurate control dwell time, the good characteristics of mass transfer heat transfer, easily realize accurate control, restrain the production of side reaction, and reaction yield is high. The method has remarkable innovation meaning and economic value, is easy for industrialization and has a wide prospect.

Preparation method of mesotrione

The invention provides a preparation method of mesotrione. The preparation method comprises: S1) carrying out a reaction on 2-nitro-4-methylsulfonylbenzoyl chloride and 1, 3-cyclohexanedione in the presence of an acid-binding agent to obtain an enol ester reaction liquid; and S2) adding a rearrangement agent as shown in a formula (I) into the enol ester reaction liquid, and performing a rearrangement reaction to obtain mesotrione. Compared with the prior art, the method has the advantages that the rearrangement agent containing unsaturated double bonds is adopted, under the synergistic effect of the double bonds, the rearrangement agent has better reactivity and reaction rate in the rearrangement reaction process, and the green and environment-friendly aftertreatment method is simple.

Selective oxidation of (hetero)sulfides with molecular oxygen under clean conditions

The development of eco-friendly and switchable catalytic systems for the conversion of a sole raw-material into distinct high-value products is a particularly attractive concept and a daunting synthetic challenge. In the present work, the first example of efficient and selective oxidation of sulfides to sulfones and sulfoxides using molecular oxygen under clean conditions was established.

Oxidation of aromatic sulfides with molecular oxygen: Controllable synthesis of sulfoxides or sulfones

The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted. The sulfoxides and sulfones could be obtained by simply switching the reaction media, i.e., bis(2-butoxyethyl)ether (BBE) or poly(ethylene glycol)dimethyl ether (PEGDME). The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents. This strategy represents an economic and eco-friendly method that could find potential applications.

Synthetic process of methyl sulcotrione

The invention discloses a synthetic process of methyl sulcotrione. 2-nitro-4-methylsulfony benzoic acid and 1,3-cyclohexanedione are added into a solvent, then, a catalyst and an addition agent are added, temperature is raised to 140-150 DEG C under stirring, and condensation reaction is directly carried out; and then, rearrangement is carried out to obtain the methyl sulcotrione. According to thesynthetic process of the methyl sulcotrione, the catalyst and the addition agent are added for dehydration, so that the condensation reaction is directly carried out on the 2-nitro-4-methylsulfony benzoic acid and the 1,3-cyclohexanedione; and then, the rearrangement is carried out to obtain a methyl sulcotrione product. Due to no adding of thionyl chloride or phosgene for chlorination, reactionsteps are reduced, and meanwhile, tail gas treatment or production safety is further avoided; and in addition, acid-binding agents are not added, and later wastewater treatment is reduced. Therefore,used raw materials are less, and greenness, environmental protection and no pollution are achieved.

Synthesis process of mesotrione

Belonging to the field of herbicide original drug preparation, the invention discloses a synthesis process of mesotrione. The process includes the steps of: (1) catalytic oxidation: taking 2-nitro-4-methylsulfonyl toluene as the raw material, and adopting oxygen as the oxidant to generate 2-nitro-4-methylsulphonylbenzoic acid under the catalysis of a manganese oxide octahedral molecular sieve loaded heteropolyacid-transition metal salt; (2) acyl chlorination: subjecting 2-nitro-4-methylsulphonylbenzoic acid to acyl chlorination to generate 2-nitro-4-methylsulfonylbenzoyl chloride; (3) condensation: carrying out condensation reaction on 2-nitro-4-methylsulfonylbenzoyl chloride and 1, 3-cyclohexanedione to obtain an enol ester intermediate reaction solution; (4) rearrangement: subjecting the enol ester intermediate to enol ester rearrangement under the catalysis of a rearrangement catalyst to obtain a crude product reaction solution; and (5) refining: refining the crude product reaction solution to obtain a mesotrione finished product. The process provided by the invention optimizes the reaction conditions, the conversion rate of each step is high, the yield and purity of the product are high, the whole production process does not involve hypertoxic materials, and the safety is high.

SYNTHESIS OF MESOTRIONE

The present disclosure relates to a method for the synthesis of mesotrione. The method comprises reacting p-toluene sulfonyl chloride with alkali metal sulphite and alkali metal bicarbonate to obtain p-toluene alkali metal sulfinate. The p-toluene alkali metal sulfinate is reacted with alkali metal salt of monochloroacetic acid to obtain p- methylsulfonyl toluene. Further, p-methylsulfonyl toluene is nitrated to obtain 2-nitro-p- methylsulfonyl toluene. 2-nitro-p-methylsulfonyl toluene is oxidized and then halogenated to obtain 2-nitro-p-methylsulfonylbenzoyl halide. 2-nitro-p-methylsulfonylbenzoyl halide is reacted with alkali metal salt of 1,3-cyclohexanedione to obtain 3-(2-Nitro-p-methyl sulfonyl benzoyloxy) cyclohexane-l-one. 3-(2-Nitro-p-methyl sulfonyl benzoyloxy) cyclohexane-1- one is reacted with base, a third fluid medium and cyanide ion source to obtain an amorphous mesotrione. The present disclosure also discloses the steps of converting the amorphous mesotrione to crystalline mesotrione having purity greater than 99 %. The process of the present disclosure for preparing mesotrione is rapid, economic, and environment friendly.

Method for producing mesotrione

The invention discloses a method for producing mesotrione. The method comprises the following steps: using an organic solvent, adding 2-nitro-4-methylsulfonylbenzoyl chloride and 1,3-cyclohexanedioneinto a reaction kettle, starting stirring, maintaining a certain vacuum degree with a negative pressure, slowly raising the temperature to 15-25 DEG C, carrying out refluxing, preserving the heat for1-3hr, bringing HCl generated by the reaction out of the reaction system in the form of gas through the negative pressure, absorbing tail gas through two stages of water, adding a rearrangement catalyst and adjusting the vacuum degree after an enol ester reaction, controlling the temperature to 25-35 DEG C, carrying out refluxing, preserving the heat for 2-4hr, steaming out the organic solvent after reaction, adding methanol for crystallization, and carrying out filtering to obtain a finished product of mesotrione. The preparation method of the mesotrione, provided by the invention, does not need to add an organic base or an inorganic base acid-binding agent, is simple and convenient to operate, generates less three wastes, is low in production cost, and is suitable for large-scale industrial production.

Preparation method of mesotrione

The invention provides a preparation method of mesotrione. The preparation method comprises the following steps: taking p-methylsulfonyl o-nitrobenzoic acid as a raw material; after carrying out acylchlorination, carrying out condensation reaction with 1,3-cyclohexanedione to obtain an intermediate 2-nitryl-4-methylsulfonylbenzoic acid-[3'-carbonyl-1'-cyclohexenol]-ester; then carrying out rearrangement of enol ester under a common catalysis effect of inorganic alkali and tertiary amine type organic alkali with relatively strong basicity, so as to obtain an acrylated cyclic 1,3-dicarbonyl compound mesotrione. According to the method provided by the invention, a virulent cyanide catalyst is not used, the reaction temperature is relatively low and the reaction time is short; a solvent can be cyclically used, the total mol yield of a prepared mesotrione product can reach 95 percent and the content is 98.5 percent; the technology is safe and environmentally friendly, has a small amount ofthree wastes and is suitable for industrial production.

Synthesis process of mesotrione

The invention discloses a synthesis process of mesotrione. The synthesis process is high in yield and high in product purity and comprises the following steps: adding concentrated sulfuric acid, an oxidation water-containing mother solution and methyl p-tolyl sulfone into a nitration reaction kettle, evenly dropwise adding nitric acid in 2-3 hours to carry out nitratlon reaction, and keeping the temperature for 60-70 minutes after finishing dropwise adding nitric acid to obtain a nitrification solution; introducing the nitrification solution into an oxidation reaction kettle, then adding V2O5 as a catalyst, dropwise adding nitric acid and controlling the reaction temperature to be 142-146 DEG C; keeping the temperature for 1-2 hours after finishing dropwise adding nitric acid; reducing the temperature of a reaction solution to 100 DEG C, then adding water, and then reducing the temperature to 48-50 DEG C, then carrying out pressure filtration to obtain an oxidation product and the oxidation water-containing mother solution, circularly rinsing the oxidation product with water; refining the oxidation product and then drying the oxidation product at 55-70 DEG C to obtain 2-nitryl-4-methylsulfonylbenzoic acid; adding sulfoxide chloride into an acyl chlorination reaction kettle, then adding 2-nitryl-4-methylsulfonylbenzoic acid and DMF for increasing the temperature and carrying out reflux reaction, distilling after reacting for 11-12 hours for separating sulfoxide chloride out, and then carrying out esterification, condensation and rearrangement.